Irrlicht is nice but the renderer really seems slower than A7. I can´t really comment on the other but I am currently checking out Horde3D which they call a "next generation graphics engine". It seems to be very fast, it is completely based on shaders and it already comes with some really nice softshadows. There is also a level editor.
The question is just what you want. Do you want a game engine or do you want to combine several libraries to your own game engine or do you want something else?
If you for example want to use Horde3D, you will need an OpenGl framework, collision detection (which could be done with a physicsengine like bullet), a gui and sound. It can be even more.
This is quite some work and you need a little programming knowledge, but I am sure that the result could be quite powerfull. Irrlicht is a bit bigger than Horde3D and for example offers basic collision detection, gui rendering, nodes and so on.